Piston.



V. E. SCHMIEDEKNECHT.

PISTON.

APPLICATION FILED JULY 14, I917.

Patented Feb. 12, 1918.

IIVVENTOR an er T UFFICE.

PISTON.

Specification of Letters Patent.

Patented Feb. 12, 1918.

Application filed July 14, 1917. Serial No. 180,511.

To all whom it may concern:

Be it known that I, VICTOR E. SCHMIEDE- KNECHT, a citizen of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented a new and useful Improvement in Pistons, of which the following is a specification.

This invention relates to pistons for internal combustion motors.

It has been ascertained to be essential that pistons of internal combustion motors should be as light as possible. In accordance with accepted construction pistons are hot low cylinders, closed at one end and open at the other, a connecting rod being secured interiorly thereof intermediate of their length by means of a transverse pin. Bosses projected inward from the side walls of the piston provide bearings for the pin. It was formerly thought that a shearing stress was exerted on this pin, and that the strain was transmitted to the side walls longitudinal thereof, and that the metal being under compression, the wall could be very thin, but failure of piston walls so constructed lead to the conclusion that the connecting rod I exerted a bending stress on the pin by which ,a lateral strain was transmitted to the walls causing them to fracture around the bosses.

This discovery necessitated an increase in the thickness of the walls and the use of a braces or brackets extended from the bosses to the piston head, or to the wall, but these of iron, of which motor cylinders are generally made. Consequently it is diflicult to get a proper fit, for if the piston is of such size as to fit in the cylinder properly when atmaximum temperature, gas and 011 will liiak by, when as at starting, the piston is coo An object of this invention is to provide a piston of minimum weight, with maximum structural strength. To the accomplishment of the foregoin and other objects, said invention consists 0 the novel'construction, association and relat1ve arrangement of parts, members and features hereinafter fully described and particularly pointed out in the claims appended hereunto.

In the drawing, wherein similar reference characters designate like parts in the several views, Figure l, is .a front elevation of an embodiment of the invention: Fig. 2, a side elevation thereof: Fig. 3, a central transverse section on Fig. 1: Fig. i, a bottom plan view: and Fig. 5, a fragmental sectional view.

Referring now in detail to the drawing, the reference character 10- designates, as an entirety, a piston, the side walls, 11- of which are provided with a plurality of grooves -l2-- adapted for the reception of piston rings. An oil groove 13 is located just below the groups of piston ring grooves, and from the floor of this groove, a plurality of perforations 15 lead through the wall of the piston, and serve as an avenue of escape for oil that may accumulate beneath the lower ring during the down stroke of the piston. The floor of this groove, is suitably inclined to facilitate the operation of drilling the holes 15. The only portions of the apron of the piston (2'. e., that portion of the wall which depends below the. pin) which bear efficiently against the walls of the cylinder are those, fore and aft, which lie in the plane of the movement of the connecting rod about the pin. The side portions (those below the ends of the pin) serve to steady the piston against lateral motion. I remove portions of said apron, leaving openings '16 each of which extends circumferentially approximately one'third of the distance around the piston, and longitudinally from a point just below the oil groove to within a spaced distance of the lower end' of the piston, leaving a band --18 of suflicient width to give a satisfactory bearing surface. Alined bearings -19 each of which has a suitable bore -20 for the reception of a piston pin, are attached at their outer ends to the -of the'apron of the piston.

It is thought that the many advantages of a piston constructed in accordancewith the foregoing description will be evident to those skilled in the art.

The walls may be considerable thinner than with the usual construction, as they are not subjected to lateral strain, the bear-- ings being supported on the inner end by a, bridge. supported by the side walls, which gives great rigidity to them, offering a maximum resistance to the bending strain exerted by the pin. The removal of portions of the apron also serves to reduce the weight.

It is to be understood that applicant re- Serves vthe right to resort to such changes, modifications, and variations, as may properly come Within the scope of the appended claims.

Having thus described, my invention so that those skilled in the art may make and use the same, 4

I claim:

1. A piston comprising a head section and a depending apron having oppositely disposed openings therein, allned bearings the outer ends of which are suspended from said headsection within said openings, and bridges sustaining the inner ends of said bearings.

2. A piston comprising a' head section, and a depending cylindrical apron, said head section being provided with a plurality of grooves for the reception of rings, and an oil groove having perforations leading from its floor to the interior of the piston, said apron having an opening below said oil groove, a bearing the outer end of which is suspended from the head section at upper edge of said opening, and atransverse bar attached respectively to the inner end of said bearing and to the apron.

3. A piston, comprising a head, and a depending apron having an opening therein, a bearing the outer end-of whichis attached to the head at the upper edge of said opening, and a transverse bar adapted to support the inner end of said bearing.

VICTOR E. SCHMIEDEKNECHT. I 

